The present technology relates to a memory element storing information based on any change of electrical characteristics observed in a memory layer including an ion source layer and a resistance change layer, to a method of manufacturing the same, and to a memory device.
A semiconductor nonvolatile memory popularly used for data storage has been a NOR or NAND flash memory. Such a semiconductor nonvolatile memory, however, has been pointed out that there are limitations on microfabrication considering the need for a high level of voltage for writing and erasing, and the limited number of electrons for injection to a floating gate.
For overcoming such limitations on microfabrication, a next-generation nonvolatile memory currently proposed is a ReRAM (Resistance Random Access Memory) or a PRAM (Phase-Change Random Access Memory), for example. These resistance change memories are each formed therein with a conductive path through migration of atoms or ions by heat or an electric field, and are each supposed to show a change of resistance value.
As an example, Japanese Unexamined Patent Application Publication No. 2009-141151 describes a memory element including an ion source layer and a high-resistance layer (resistance change layer) between two electrodes. The ion source layer contains a chalcogenide element and a metallic element, and the high-resistance layer is a gadolinium oxide film. In the memory element, application of a voltage causes the metallic element (ions) to move, thereby forming a conductive path in the high-resistance layer.